Adaptive Wheat Management: A System for Managing Wheat Based on Plant Physiology and Growth Responses to Environmental Conditions.

摘要

Due to its ability to adapt to changing environmental conditions, wheat is one of the more difficult crops to manage. Since wheat has the ability to adapt to changing environmental conditions, it is essential for wheat growers to focus on an adaptive management approach that changes from season to season based on current and predicted environmental conditions rather than a prescription management approach that is the same each season. Two keys that are necessary to the successful implementation of an adaptive management system are 1) the ability to understand the plant growth response to different environmental conditions, and 2) the ability to predict weather conditions during critical growth periods that influence the development of each yield component.;To determine plant growth responses to the environment, this research focused on the environmental conditions and management practices that influence leaf development. In particular, the influence of planting date and environmental conditions following planting were of interest. The selection of planting date of wheat is an essential component in successful wheat production as it directly influences early leaf and fall tiller production which correspond to high yields. However, the proper planting date often varies with year. When a cold fall is forecasted, it is essential to plant early in order to develop adequate fall tillers before dormancy. When warm temperatures last into December, the planting date may be delayed. A two-year study examining leaf development at two planting dates was performed. In 2012-13, the later planting date resulted in greater fall tillers and higher yields due to a shorter phyllochron interval in November than in December. However, in 2013-14, more fall tillers and higher yields were produced in the early planting date as a cold December, January, and February severely limited GDD accumulation which reduced the wheat planted late had to develop tillers.;In the second study, the grain fill period was examined in order to quantify kernel set in response to growing conditions in April and May and how it can be impacted by environmental and management factors such as light interception, fungicide, and nitrogen. The shaded treatment resulted in the lowest rate of grain fill and yields, which indicate the importance of proper light interception during the grain fill period. While neither a fungicide nor nitrogen application at GS70 had an effect on the rate of grain fill or yield, a fungicide application may be necessary when there is intense disease pressure which will limit light interception during the grain fill period.;Since there is a need to be able to predict weather conditions during critical growth periods, it is necessary to use some type of weather pattern as a guide for determining planting date. Therefore, we have attempted to use the El Nino Southern Oscillation and the North Atlantic Oscillation weather events to properly select a planting date based on which pattern minimizes the time necessary for the plant to develop its first tiller. Results show that the El Nino and Cool October North Atlantic Oscillation phases often provide the most favorable conditions for fall tiller production.